The invention relates generally to the field of radiant cooktop appliances and more particularly, to temperature measurement and control system for such cooktops.
Various types of cooking appliances employ radiant cooktops such as, glass-ceramic cooktops. Such cooktops have advantages such as pleasing appearance and easy cleanability. In conventional radiant cooktop appliances, a cooktop is heated by radiation from heating units located below the cooktop. The heat is conducted from the cooktop surface to a cooking utensil placed over the cooktop surface for performing the cooking activities. For controlling the cooking features of cooking appliances with radiant cooktops, it may be useful to measure the temperature of the cooking utensil placed over the cooktop, such as a pot or pan.
Many specific techniques have been developed and are in use for measurement of the temperature of a cooking utensil over radiant cooktops. For example, in some systems, a temperature sensor coupled to the cooking utensil measures the temperature of the cooking utensil. However, such techniques require holes to be drilled through the cooktop surface to facilitate contact between the temperature sensor and the cooking utensil, resulting in reduced cleanability, one of the key attractive features of radiant cooktops.
Certain other systems presume the temperature of the underside of the cooktop surface as a measure of the temperature of the cooking utensil. This technique does not provide accurate estimation of the temperature of the cooking utensil, as it does not take into account the variability of the temperature drop across the cooking utensil and the surface of the cooktop. Such variation in the temperature drop occurs due to the varying thermal resistance of the interface between the cooking utensil and the surface of the cooktop that is dominated with the air gap between the cooking utensil and the absorption properties of the cooking utensil.
Therefore, it would be desirable to develop a technique for a substantially accurate temperature measurement of a cooking utensil placed over a radiant cooktop. Furthermore, it would be advantageous to control operation, such as power input to the radiant cooktop, based upon such temperature measurement data.